On the use of the Gauss filter in modal parameter estimation

The paper deals with the modal parameter estimation from the instantaneous envelope and phase-achievable by the Hilbert transform-of a single mode filtered from a frequency response function by the Gauss filter. It is possible, modulating the Gauss function, to put its maximum on the desired frequency, for instance on the peak of the mode of interest. Then a suitable choice of the parameter, which determines the sharpness of the Gauss function, permits to face the problem of modes with different damping, also in the highest frequencies of the band. This last point has been the major drawback of similar estimation methods based on the Gauss-Morlet wavelet. The results presented have been obtained both from numerical simulations and from experimental tests: the first ones achieved from synthesised impulse response functions of single and multiple lumped degree of freedom systems, and the second ones carried out on a simple structure (clamped aluminium plate). (C) 2000 Academic Press.